While many people choose to have soft tissue fillers injected into their facial tissue to smooth out wrinkles, some may experience unpleasant side-effects in the form of tender subcutaneous lumps that are difficult to treat and which — in isolated cases — have led to lesions that simply will not heal. Research recently published by the University of Copenhagen now supports that, despite the highest levels of hygiene, this unwanted side-effect is caused by bacterial infection.

‘Previously, most experts believed that the side effects were caused by an auto-immune or allergic reaction to the gel injected,’ said Morten Alhede, a postdoc at the Department of International Health, Immunology and Microbiology, University of Copenhagen.

‘Research involving tissue from patients and mouse models has now shown that the disfiguring lesions are actually due to bacteria injected in connection with the cosmetic procedure. What is more, we have demonstrated that the fillers themselves act as incubators for infection, and all it takes is as few as ten bacteria to create an ugly lesion and a tough film of bacterial material — known as biofilm — which is impossible to treat with antibiotics.’

The study results have just been published in the journal Pathogens and Disease.

Biofilm is resistant to antibiotics

According to the American Society for Aesthetic Plastic Surgery (ASAPS), treatment with products based on hyaluronic acid constitutes the second-most popular non-surgical cosmetic procedure in the United States. The precise figures for Denmark are not known, but there can be no doubt that the numbers are rising rapidly, and a rise in the number of treatments will inevitably make the side-effects more evident.

‘Because a lot of cosmetic practitioners refuse to accept that side-effects from filler procedures are caused by bacteria, claiming that such problems are caused by allergic reactions, the usual procedure has been to treat with steroids. This is actually the worst possible treatment because steroid injections exacerbate the condition and give the bacteria free rein. Fortunately, many of the filler producers have now become aware of the risk of bacteria and recognise that the gel can act as a bacterial incubator,’ said Associate Professor Thomas Bjarnsholt from the Department of International Health, Immunology and Microbiology.

‘The problem will become very serious when the treatment becomes so widespread that people are able to walk in off the street to have their wrinkles smoothed out. Experts recommend keeping facial skin free from make-up for a month before undergoing a treatment involving fillers. Good hygiene is always important. Even when you abide by all the rules and regulations, it is difficult to avoid bacteria completely as they are often buried far below the surface of the skin.’

Beauty with consequence

Researchers estimate that between 1:100 and 1:1000 — depending on the type of filler — develops an unfortunate bacterial infection which, in the worst-case scenario, may leave the person in question with a permanently disfigured face.

The biofilm that can develop in the wake of a filler treatment is resistant to antibiotics. ‘The good news is that infections can be prevented by prophylactic antibiotic treatment, i.e. injecting antibiotics together with the filler itself during the cosmetic treatment process. Our new research emphasises how important it is for all practitioners to follow this procedure to prevent the unwanted complications,’ said Morten Alhede.